It's back again for me this morning on my Primary and occassionally on the secondary account on the same server - UK877. The other two secondaries are ok so far. I've tried the usual work arounds with no luck.
I haven't been able to access my primary email account all day. This is the second time it has happened recently.
I'm really going to have to sort out an alternative email solution. I just can't rely on BT email any more.